One issue with many conventional cellular networks, including conventional LTE networks, is frequent handover, particularly in heterogeneous deployment scenarios that include macro-cells and pico-cells. For example, a primary cell (PCell) may be served from a macro-cell and a secondary cell (SCell) may be served from a pico-cell. Since the coverage of a pico-cell may be much smaller than that of a macro-cell, user equipment (UE) may need to handover to a macro-cell or another pico-cell if the UE is connected only to the pico-cell. On the other hand, if the UE is connected to the macro-cell, handover may not be required, however offloading to the pico-cell would not be provided. To achieve offloading and reduce the frequency of handover, carrier aggregation (CA) between a macro-cell and pico-cell may be performed. In conventional LTE systems, CA is only supported between cells in the same enhanced Node B (eNB). However, macro-cells and pico-cells in a heterogeneous deployment scenario may be associated with different eNBs.
In order to reduce power consumption, a UE may engage in discontinuous reception (DRX) operations during which the UE may be configured to receive a control channel during certain periods of time. The use of CA presents several issues for DRX operations particularly when a macro-cell and a pico-cell are served by different eNBs. For example, when serving cells are associated with different eNBs, it becomes difficult for a UE to determine the control channel reception times as well as other DRX related parameters. Other issues associated with the use of CA for DRX operations when serving cells are associated with different eNBs include uplink scheduling, random access and transmission of a buffer status report (BSR).
Thus there are general needs for devices and methods that reduce address the issues associated with DRX during inter-eNB CA, particularly serving cells are associated with different eNBs.